Human IKZF1 blocking peptide

Genome-wide association studies (GWAS) have proved the association of IKZF1 polymorphisms with childhood acute lymphoblastic leukemia (ALL). In the present study, we aimed to inspect the impact of IKZF1 gene polymorphisms and childhood ALL in a sample of Iranian population who live in south east of Iran. This case-control study was done on 110 children diagnosed with ALL and 120 healthy children. The IKZF1 (rs4132601 T > G, rs11978267 A > G, rs11980379 T > C, and rs10272724 T > C) polymorphisms were determined using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The results showed that rs4132601 T > G polymorphism increased the risk of ALL in the codominant (OR = 2.96, 95 % CI = 1.58-5.54, p = 0.0008, TG vs TT; and OR = 2.75, 95 % CI = 1.31-5.76, p = 0.0094, GG vs TT) and dominant (OR = 2.89, 95 % CI = 1.61-5.19, p = 0.0004, TG + GG vs TT) inheritance models. On the other hand, the rs4132601 G allele increased the risk of ALL (OR = 1.86, 95 % CI = 1.28-2.96; p = 0.0011) in comparison with the T allele. We have also showed that rs11980379 T > C variant increased the risk of ALL in codominant (OR = 2.43, 95 % CI = 1.28-4.60, p = 0.0076, TC vs TT; and OR = 2.35, 95 % CI = 1.14-4.85, p = 0.0291, CC vs TT) and dominant (OR = 2.40, 95 % CI = 1.32-4.36, p = 0.0038, TC + CC vs TT) inheritance models. The rs11980379 C allele increased the risk of ALL (OR = 1.59, 95 % CI = 1.10-2.31, p = 0.0151) compared with T allele. Our study also revealed that the rs10272724 T > C polymorphism increased the risk of ALL in codominant (OR = 2.18, 95 % CI = 1.19-3.99, p = 0.0115, TC vs TT; and OR = 2.67, 95 % CI = 1.24-5.77, p = 0.0131, CC vs TT) and dominant (OR = 2.31, 95 % CI = 1.30-4.08, p = 0.0049, TC + CC vs TT) inheritance models. On the one hand, the rs11980379 C allele increased the risk of ALL (OR = 1.70, 95 % CI = 1.17-2.46, p = 0.0062) compared with T allele, while the rs11978267 A/G polymorphism was not associated with ALL risk. In conclusion, our findings confirm the impact of IKZF1 polymorphisms on childhood ALL risk in a sample of Iranian population. Further studies with larger sample sizes and different ethnicities are needed to confirm our findings.

Background: Ikaros, which is encoded by IKZF1, is a transcriptional factor that play a critical role in hematopoiesis. Somatic IKZF1 alterations are known to be involved in the pathogenesis of leukemia in human subjects. Recently, immunodeficiency caused by germline IKZF1 mutation has been described. Objective: We sought to describe the clinical and immunologic phenotypes of Japanese patients with heterozygous IKZF1 mutations. Methods: We performed whole-exome sequencing in patients from a dysgammaglobulinemia or autoimmune disease cohort and used a candidate gene approach in 4 patients. Functional and laboratory studies, including detailed lymphopoiesis/hematopoiesis analysis in the bone marrow, were performed. Results: Nine patients from 6 unrelated families were identified to have heterozygous germline mutations in IKZF1. Age of onset was 0 to 20 years (mean, 7.4 years). Eight of 9 patients presented with dysgammaglobulinemia accompanied by B-cell deficiency. Four of 9 patients had autoimmune disease, including immune thrombocytopenic purpura, IgA vasculitis, and systemic lupus erythematosus. Nonautoimmune pancytopenia was observed in 1 patient. All of the mutant Ikaros protein demonstrated impaired DNA binding to the target sequence and abnormal diffuse nuclear localization. Flow cytometric analysis of bone marrow revealed reduced levels of common lymphoid progenitors and normal development of pro-B to pre-B cells. Conclusions: Germline heterozygous IKZF1 mutations cause dysgammaglobulinemia; hematologic abnormalities, including B-cell defect; and autoimmune diseases.